Linked Life Data

9393456

Source:http://linkedlifedata.com/resource/pubmed/id/9393456

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1997-12-24
pubmed:abstractText
The glycopeptide antibiotic vancomycin blocks cell wall synthesis in Escherichia coli only when it can reach its target site in the periplasm. In vivo, sensitivity to vancomycin is enhanced in the presence of the hemolysin (hly) determinant of E. coli or its translocator portion hlyBD. Two different mutations in hlyD alter the cell's susceptibility to vancomycin: mutations in the tolC-homologous region of hlyD increase vancomycin resistance, whereas mutations at the 3'-terminus of hlyD lead to hypersensitivity to vancomycin and to the accumulation of large periplasmic and cytoplasmic pools of this antibiotic in E. coli. These effects are only observed in the presence of functional HlyB and TolC, the two other components of the hemolysin secretion machinery. A defect in TolC causes hyperresistance to vancomycin, even when present together with a mutant HlyD protein which in the presence of TolC renders E. coli hypersensitive to vancomycin. Lipid bilayer experiments in vitro revealed specific interactions between TolC and vancomycin or HlyD protein. Second-site suppressor mutations in hlyD and hlyB were obtained, which abolish the hypersensitive phenotype caused by the 3'-terminal mutations in hlyD. Our results are compatible with the idea that (a) TolC, together with the TolC-homologous part of HlyD, forms a pore in the outer membrane through which hemolysin is released and vancomycin taken up; and (b) the C-terminal sequence of HlyD interacts with periplasmic loop(s) of HlyB to form a closed channel spanning the periplasm.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0026-8925
pubmed:author
pubmed:issnType
Print
pubmed:volume
256
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
306-19
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
In vivo and in vitro studies on interactions between the components of the hemolysin (HlyA) secretion machinery of Escherichia coli.
pubmed:affiliation
Lehrstuhl für Mikrobiologie, Theodor-Boveri-Institut für Biowissenschaften, Würzburg, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't